Mercruiser GM Big Block Center Rise Exhaust Manifold | Sierra 18-1957-2
$334.00
Competitor Price:
$425.68
Center rise exhaust manifold fits Mercruiser GM 7.4L & 8.2L CID marine engines.
- Mercruiser exhaust manifold
- Direct replacement manifold fits Mercruiser GM V8 454 and 502 cu. in. engines with center riser
- For Mercruiser 330, 340, & 454 Magnum model engines
- Interchangeable between port and starboard side
- Heavy duty cast iron
- Painted black
- Includes all gaskets, short riser studs, drain elbow, and plugs
- Manifold mounting kit P/N 18-8532 – sold separately
- Replaces Mercruiser 89011A8, 807078A2, 807078A4, 807078A6, 807078T09, 807078T10
- Replaces Mallory 9-40506
- Replaces Osco 9011A
- Replaces Sierra 18-1957, 18-1957-1
Most in-stock orders ship within 24 hours. Orders placed by 1:00 PM EST typically ship the same business day, subject to availability.
Average delivery time within the Continental U.S. is 3–7 business days.
Expedited shipping options are available on select products. Weekend delivery is not available.
Oversized items, drop-shipped products, and shipments to Alaska, Hawaii, or international destinations may require additional time or shipping costs.
Tracking information is emailed once your order ships.